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Randomized clinical trial of an elastomeric sealant for hemostasis in thoracic aortic surgery

20/09/2022 - Department of Thoracic and Cardiovascular Surgery, Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan


This study aimed to demonstrate the efficacy and safety of a newly developed elastomeric sealant, which does not require any blood coagulation system to exert its effect, during thoracic aortic surgery.


This is a multicenter, randomized study conducted in six hospitals in Japan. A total of 81 patients undergoing replacement surgery of a thoracic aortic aneurysm using cardiopulmonary bypass were randomized with a ratio of 2:1 for those patients designated to receive the sealant (Group S, 54 patients) or those without the usage of the sealant, but who were allowed to be treated with any other hemostatic method or other material (Group C, 27 patients).

Figure 1: Patient allocation

The primary endpoints were bleeding from each anastomosis at two time points: immediately before applying protamine and 15 min after applying protamine. The patients were followed for 6 months.

Figure 2: Process of the sealant reaction

Figure 2 shows a schematic presentation of the process of the sealant reaction when applied to tissue. Because the tissue surface is always moistened and covered with water, the sealant starts reacting immediately when applied to the tissue surface. The sealant penetrates places where water molecules exist due to its hydrophilic nature and starts reacting with the water to form a seal tightly attached to the tissue. During the reaction, small carbon dioxide gas bubbles are generated by the sealant.


The number of anastomoses checked for bleeding was 196 in Group S and 117 in Group C. Before protamine sulfate administration, complete hemostasis was obtained in 155 anastomoses (79%) in Group S compared to 45 anastomoses (38% ) in Group C (p < 0.001). Fifteen minutes after the administration of protamine sulfate infusion, bleeding stopped completely in 173 anastomoses (88%) in Group S and in 71 anastomoses (61%, p < 0.001) in Group C. Between the two groups, there were no marked differences in the patient background or in the incidence of major adverse events.

Figure 3: Percentage of complete hemostasis between the two groups


The sealant is effective in achieving hemostasis, even under fully heparinized conditions. The sealant is safe and effective in thoracic aortic surgery, one of the most demanding surgical situations for hemostasis.